Want a NON-LEAKING valve cover install on Toyota Cressida w/7MGE DOHC 6

"hylomar".

avoid that rtv silicone crap like the plague.

Hylomar seems to think they make RTV silicone, kindly correct them at your earliest convenience.

apparently you're unaware that most of us just use what we can get at the flaps. or online.

and would now be an inconvenient time to point out that with another half-second of research, you could have found the information you were obviously looking for but somehow overlooked at:

I looking for nothing but instead supplied incontrovertable evidence via the manufacturer's website of the very product you recommended both for and against.

You provide yet another pretentious, pointless, wholly failed rebuttal, but I expected nothing less from you.

On 01/16/2012 07:06 PM, Hoof Headed idiotically stalked:

ok, i guess not.

Should your confusion continue to persist, allow me to quote from my aforementioned mfg's site: "Hylomar RTV silicone sealants are used globally to seal engines, gearboxes & transmissions by leading manufacturers".

On 01/16/2012 07:16 PM, Hoof Headed idiotically stalked:

should your idiocy continue to persist, allow me to re-quote what you're incapable of comprehending:

' "hylomar".

avoid that rtv silicone crap like the plague.'

i would have thought "avoid silicone" would have been fairly understandable. similarly, i would have thought that "hylomar" was understandable given both the "avoid silicone" statement AND that you /cannot buy/ anything /but/ their polyester sealant through normal retail channels.

and failure to understand the two in context, in the same post? that's just plain simple idiocy.

[and just in case you're /still/ too retarded to get it, read this:

"Silicone O-Rings

Limitations: Avoid ... aliphatic and aromatic hydrocarbons (i.e. fuels) and petroleum oils."]

So do some Toyota factory manuals recommend RTV silicone for valve cover gaskets, like at the inside sharp corners and around half-moon rubber plugs?

i don't know - but i'd guess from the way you ask the question that the english version does. what i /do/ know is that silicone is unsuited for long term oil exposure. and it has implications for oxygen sensors - apparently silicone leaching into oil gets burned and on exit, poisons the zirconia. [silicone is highly pervasive - it's a huge no-no in the microscopy, mass spectrometry and chemical analysis world.]

honda recommends a non-setting gasket material for those locations, and the polyester material that hylomar is made of meets that specification. it also has better temperature stability, on both ends of the scale.

i've used it for many years and have never had a problem with it with oils, fuels or coolants. unlike silicone where it may not seal [it skins very quickly and this can be an issue] and can be a devil to remove.

I used Permatex Ultra Copper RTV silicone, and all the Ultra series RTV silicones are claimed to be safe for oxygen sensors because they give off lower amounts of fumes (alcohol cure) than other silicones do (vinegar cure), and Ultra Copper and Ultra Blue are supposed to be 3x more resistant to oils than are regular RTV silicones. Permatex says some of their RTV silicones are used on the production lines of several car makers and are OEM approved by others.

Catalog:

OTOH when I had an oil pan leak in a nearly new Ford, the car dealer used some factory-approved RTV silicone that made the oil look like pea soup.

That said, there *is* "sensor safe" RTV silicone available. Whether it is really 100% sensor safe is another story.

My first choice would be to see if there were a metal-core rubber reusable gasket available for your application, rather than the typical cork.

If that fails, I have had good luck with plain old Permatex No. 2. It's messy stuff, but cleans up with rubbing alcohol (but seems pretty much impervious to both gasoline and motor oil.)

nate

Still trying to pitifully pretend, feebly dispute and hopelessly obfuscate the undeniable, despite the appearance right there in black and white on their website, and your words above in which you now delusionally attempt to rationalize and characterize simply as clumsy original remarks. You truly are not an iota shy of totally pathetic and in the most desperate conceivable need of professional help.

As he pens even more pretentiously confused and ridiculous blanket statements.

You dont have to avoid RTV silicone at all. Loctite and others have sealants that are safe for engines with oxygen sensors and are good to high temperatures.

READ THE INSTRUCTIONS before you buy a sealant. They will tell you if you can use it safely, and what metals or plastics you can bond.

LET IT CURE before you put the engine back in service.. I dont care what you may have heard, extended cure times (12-24 hours) may be to your ultimate benefit.

USE NEW HIGH QUALITY GASKETS...

CHECK to be sure your valve cover gasket contact area is not warped, dented, or otherwise damaged. Cheap tinny valve covers (like GM has enjoyed in the past) are easy to deform and may leak if you torque them down too tightly.

here's the thing with rtv - in the absence of knowledge of better alternatives, it's what people think they /have/ to use. and the english toyota manuals, absent knowledge of better alternatives, are apparently no exception. [honda want to sell you and thus recommend /their/ own proprietary goop, which is remarkably like hylomar.]

silicone is rare in oem manufacture - because it's poor in oil apps. and its primary manufacturers, dow and g.e. have very aggressive sales operations. there are a /ton/ of applications into which silicone is sold where it's far from the best or even the most cost effective solution, but it's still sold into those applications anyway.

the automotive aftermarket sealant niche is the perfect example - rtv kinda works initially because of consistency, for a while. but all the cars i've worked on with really bad oil leaks are invariably "sealed" with silicone that has [inevitably] failed. and as you observe, it's not good for the oil either.

hylomar [the stuff you can buy in the normal retail channels] is an excellent solution - and it lasts. best of all, re-work just needs acetone to clean it off - no scraping that silicone crap and getting bits all over which then float off and block oil channels.

Doc wrote in news:9ef308af-4a60-4651-b95a- snipped-for-privacy@l19g2000yqj.googlegroups.com:

If the gaskets are FLAT, and do not take sharp vetical detours around cam bearing caps and the like, install the new gaskets BONE-DRY. Do not use RTV sealants. Make sure any trace of oil is cleaned off. Any oil residue on the mating surfaces will result in a steady seepage that will make a mess of your engine.

If the gaskets take sharp vertical detours around the cam caps (typical of Honda engines), use Permatex Ultra Black or Ultra Grey on the sharp corners. As above, gaskets and mating surfaces MUST be free of oil residue.

It's best to use OE gaskets (Toyota dealer). OE is the best-made, fits best, and lasts longest.

Maybe Toyota gaskets do, but this is not an universal truth. Remember back to the GM gaskets of the 90's that were just pieces of garbage...Aftermarket then engineered a gasket built to last.

"hls" wrote in news: snipped-for-privacy@giganews.com:

That does not say much for GM, does it?

When I said "OE is best", I did not refer to the domestics, but to Toyota explicitly.

GM OEM is usually a sure bet too, but you can save some money in most cases by going aftermarket. HLS is ranting on about the OEM 3800 LIM gaskets, which had inadequate design. His failed. But you could buy the same inadequate design as aftermarket Felpro. When they got smart and went to metal clad gaskets, GM had the same type gaskets Felpro was selling. But some parts guys at GM would still sell you the bad design gasket. I suspect Felpro and GM consulted each other on these gaskets. Should have had the GM parts guys stop selling the bad gaskets too.

My son and I replaced his 3800 LIM with a GM metal-clad, and his upper plenum with a Dorman, per recommendations from real mechanics. Don't know if that GM LIM technically OEM, since it was called something like "2nd improvement." We didn't wait for the original OEM to fail, but we had the advantage of the problem becoming well know by then. HLS got screwed by GM. Not unusual for GM "early-adopters." By the time I buy them I usually know all about their problems.

The 3100 LIM gaskets are also known to fail, and I did those on my Lumina at about 160k miles when I decided I would keep it for a while. That one I wasn't aware of the LIM gasket problem when I bought it cheap ($2500) with 100k miles on it. Used a Felpro metal-clad set to replace the plastic clad. The old gasket looked pretty bad. Again, followed the recommendations of those who do these all the time.

In my experience driving and fixing my GM cars, aftermarket parts availability is a bonus. And keeping a valve cover from leaking is a non-issue where ever you source the gasket. Sealer, if used, is like anything else. Look at the shop manual, or talk to a competent mech who does it for a living. It's best to find a forum. GM has plenty for most models I've seen. Actual brand mechanics frequent them, as used to happen here. Or come here and roll the dice. Hope somebody actually has experience on the 7MGE DOHC 6 and isn't talking out of there ass. The OP didn't give details, but if the leaking gasket is a chronic problem it's possible a plugged PCV is causing pressurization of the valve covers.

--Vic

. l